In the year-ago quarter, the mobile giant reported adjusted earnings of 74 cents on $40.89 billion in revenue.

The postpaid churn rate, or the percentage of subscribers who cancel their service, was 0.84 percent for the quarter. The total was lower, therefore better, than Wall Street's expectation of 1.08 percent, according to StreetAccount.

Although earnings and revenue came in slightly below Wall Street expectations, AT&T maintained its full-year guidance. Analysts project that AT&T will report full-year earnings of $2.93 per share on $160.86 billion in revenue, according to Thomson Reuters consensus estimates.

After the report, shares of AT&T slipped 1 percent in after-hours trade.

On Monday, AT&T extended its deadline to close its proposed acquisition of Time Warner amid pending regulatory approval.

On the earnings call, CFO John Stephens said AT&T still expects the deal to close by year-end.

But the mobile giant and entertainment conglomerate face political headwinds amid increased scrutiny of mega-mergers. Shortly after the deal was first announced, then-candidate Donald Trump said his administration would not approve the deal.

Blockbuster deals are also being targeted by the other side of the aisle. In July, Democrats rolled out a new economic platform, including a push for post-merger reviews. Part of the agenda calls for a new competition advocate that the Democrats have nicknamed the "Trust Buster."

Shares of AT&T have fallen about 18 percent so far this year. On Tuesday, the stock hit a fresh 52-week intraday low of $34.86.